Of course, we can’t know this for sure. Ellenberg admits this study is for “entertainment purposes only.” The number is based on where in the book Kindle users tend to highlight passages (Kindle users’ highlighted passages are made public). Ellenberg explains:

How can we find today’s greatest non-reads? Amazon’s “Popular Highlights” feature provides one quick and dirty measure. Every book’s Kindle page lists the five passages most highlighted by readers. If every reader is getting to the end, those highlights could be scattered throughout the length of the book. If nobody has made it past the introduction, the popular highlights will be clustered at the beginning.

In the case of Piketty’s book, the last of the top-five most highlighted passages occurs on page 26. That’s not very far, considering the book is more than 700 pages long. So even with a huge margin of error, it seems few people are actually reading Piketty’s book.

But should anyone be surprised? It’s a dense pseudo-textbook on economic theory. I’m just glad people are thinking about these issues, even if wrongly.